The Role of PDGFs and PDGFRs in Colorectal Cancer

Introduction. Colorectal cancer (CRC) is an important cause of morbidity and mortality worldwide. Angiogenesis was reported as one important mechanism activated in colorectal carcinogenesis. Tumor microenvironment associated angiogenesis involves a large spectrum of signaling molecules and deciphering their role in colorectal carcinogenesis still represents a major challenge. The aim of our study is to point out the diagnosis and prediction role of PDGF family and their receptors in colorectal carcinogenesis. Material and Methods. A systematic search in Medline and PubMed for studies reporting the role of platelet-derived growth factors (PDGFs) and their receptors (PDGFRs) in tumor biology related to CRC was made. Results. PDGFs are important growth factors for normal tissue growth and division, with an important role in blood vessel formation. PDGFs/PDGFRs signaling pathway has been demonstrated to be involved in angiogenesis mainly by targeting pericytes and vascular smooth muscle cells. High levels of PDGF-BB were reported in CRC patients compared to those with adenomas, while elevated levels of PDGFR α/β in the stroma of CRC patients were correlated with invasion and metastasis. Moreover, PDGF-AB and PDGF-C were correlated with early diagnosis, cancer grading, and metastatic disease. Conclusions. Both PDGFs and PDGFRs families play an important role in colorectal carcinogenesis and could be considered to be investigated as useful biomarkers both for diagnosis and treatment of CRC

The Impact of miRNA in Colorectal Cancer Progression and Its Liver Metastases

Colorectal cancer (CRC) is one of the most commonly diagnosed malignancies with a high incidence and mortality rate. An essential challenge in colorectal cancer management is to identify new prognostic factors that could better estimate the evolution and treatment responses of this disease. Considering their role in cancer development, progression and metastasis, miRNAs have become an important class of molecules suitable for cancer biomarkers discovery. We performed a systematic search of studies investigating the role of miRNAs in colorectal progression and liver metastasis published until October 2018. In this review, we present up-to-date information regarding the specific microRNAs involved in CRC development, considering their roles in alteration of Wnt/βcatenin, EGFR, TGFβ and TP53 signaling pathways. We also emphasize the role of miRNAs in controlling the epithelial⁻mesenchymal transition of CRC cells, a process responsible for liver metastasis in a circulating tumor cell-dependent manner. Furthermore, we discuss the role of miRNAs transported by CRC-derived exosomes in mediating liver metastases, by preparing the secondary pre-metastatic niche and in inducing liver carcinogenesis in a Dicer-dependent manner